Related Experiment Video
Updated: Dec 24, 2025
07:32
Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
1.7K
Changes in maximum lip-closing force after extraction and nonextraction orthodontic treatments
Tae-Hyun Choi1, So-Hyun Kim1, Cheul Kim2
1Department of Orthodontics, Seoul National University Bundang Hospital, Section of Dentistry, Seoul National University, Seongnam, Korea.
Korean Journal of Orthodontics
|April 8, 2020
Summary
Orthodontic treatment involving premolar extractions significantly increases maximum lip-closing force (MLF) more than nonextraction treatment. This finding highlights the impact of extraction mechanics on lip function.
Area of Science:
- Orthodontics
- Dental Biomechanics
- Facial Aesthetics
Background:
- Orthodontic treatment aims to improve dental and facial aesthetics.
- Understanding the impact of different orthodontic techniques on orofacial muscle function is crucial.
Purpose of the Study:
- To evaluate changes in maximum lip-closing force (MLF) after orthodontic treatment.
- To compare MLF changes between nonextraction and premolar extraction cases.
- To correlate MLF changes with dentoskeletal alterations.
Main Methods:
- Retrospective study of 17 nonextraction and 15 extraction female patients.
- Measurements included lateral cephalograms, dental models, and MLF via Lip De Cum LDC-110R® device at T0 (before) and T1 (after) treatment.
- Statistical analysis to assess changes and correlations.
Main Results:
- Both groups had similar skeletal patterns, but the extraction group showed increased incisor proclination and lip protrusion initially.
- The extraction group exhibited more pronounced reduction in arch dimensions and incisor retroclination.
- MLF significantly increased in the extraction group, more so than in the nonextraction group.
Conclusions:
- Extraction orthodontic treatment leads to a greater increase in MLF compared to nonextraction treatment.
- Increased MLF correlated with changes in interincisal angle, intermolar width, arch depth, and incisor-mandibular plane angle.
Keywords:
Dental arch morphologyLip-closing forceNonextraction orthodontic treatmentPremolar extraction
